Population time budget for the yellow-bellied marmot

Abstract

Time budgets for 17 behaviors were analyzed for cohort, day-period, season-period and interactions among the main effects for three colonies of yellowbellied marmots in the Upper East River Valley in western Colorado. These effects explained up to 79% of the variation in the behaviors. Marmots allocated more time (40-60%, 110-265 min daily) above-ground to sitting/lying than to any other activity. Foraging was the other major activity (12-23%, 37 to 94 min daily). Vigilance/alert varied from 1.1 to 14.5% and from 12.0 to 71.7 min daily. Social status affected the time budget, especially time allocated to vigilance/alert. All other behaviors averaged about 5% or less except for out-of-sight and enterburrow. The adult male cohort spent significantly more time above-ground than all other cohorts and reproductive females allocated significantly more time to foraging than the other cohorts. The amount of time spent above-ground decreased linearly from the down-river site to the up-river site. The proportion of time spent above-ground was significantly less at mid day than in the morning or afternoon. Above-ground activity was lowest during gestation, increased during lactation, remained high during early post-lactation, and declined during the final season-period. The following significant relationships common to the three colonies suggest species characteristics or common environmental influences: more time allocated to foraging and foraging-vigilance in the afternoon and more time allocated to foraging-alert, alert, and locomotion during gestation and lactation than during post-lactation. Marmots adjust their behaviors according to prevailing conditions. The remaining significant relationships can be attributed to specific age-sex cohorts or to habitat differences. Because marmots allocate so much time to sitting/lying, we suggest that energy budgets are not constrained by foraging time but by time required to process ingested food. Similarly, time spent vigilant/alert does not seem to constrain energy intake. Social behavior is not limited by time, but could easily be expanded by spending less time inactive. In general, there do not seem to be tradeoffs among activities. Among other species of ground-dwelling sciurids, social behavior occupies a small proportion of the time budget, but the amount of time allocated to foraging and sitting/lying varies widely.

The effect of vegetation cover on vigilance and foraging tactics in the fat sand rat Psammomys obesus

“…Similar results were reported for the yellow-bellied marmot Marmota flaviventris, which allocated much time to resting, and neither foraging time nor vigilance seemed to constrain energy intake (Armitage et al 1996). Analogously, variation in vigilance in the wedge-capped capuchin Cebus olivaceus also appeared not to depend on time needed for foraging or the risk of predation but rather was related to intrinsic individual characteristics (Fragaszy 1990).…”

Helpers influence on territory use and maintenance in Alpine marmot groups

“…The decrease in the frequency of marking behaviour over the summer, in particular after the emergence of the pups in July, can be explained by the reproductive role played by this behaviour and/or by the variation of time spent performing other important behaviours. Whereas foraging seems to increase in August in Alpine marmot (Perrin et al 1993a) its direct variation throughout the season has not being observed in other similar species (Marmota flaviventris: Armitage et al 1996). An alternative possible reason explaining the seasonal decrease of scent marking may derive from the observed increase in body fat accumulation during the fall probably caused by a reduction in energy expenditure with the season (e.g.…”

Pastoralist disturbance effects on Himalayan marmot foraging and vigilance activity

“…This may account for greater foraging times we recorded for Himalayan marmots, as compared to other species (e.g. Johns and Armitage 1979;Taulman 1990;Armitage et al 1996). For example, Armitage et al (1996) found that yellow-bellied marmots in Colorado spent more time foraging during lactation.…”

“…The percentage of time spent foraging by Himalayan marmots was higher compared with other marmot species, such as yellow-bellied marmots (up to 23 %; Armitage et al 1996;Armitage and Chiesura Corona 1994), golden marmots (about 30 %; Blumstein 1998), hoary marmots (up to 40 %; Barash 1980;Taulman 1990), Olympic marmots (about 33 %; Griffin et al 2007). Time spent foraging by marmots is influenced by several factors, including food availability, season, sex, reproductive status, and other environmental factors (Armitage et al 1996;Armitage 2014). In comparison to other marmot studies, we recorded differences in the foraging time of Himalayan marmots, which may be explained by seaonsal differences in study timing, and availability of food resources for different marmot species.…”